Industrial & Engineering Chemistry Research, Vol.59, No.39, 17564-17574, 2020
Fixed Bed Reactor Pyrolysis of Rape Straw: Effect of Dilute Acid Pickling on the Production of Bio-oil and Enhancement of Sugars
To investigate the influence of dilute acid pickling on pyrolysis behavior and product distribution during rape straw (RS) pyrolysis, HCl, HF, and HCl + HF were selected. Proximate and ultimate analysis, ICP-AES, SEM, and BET were employed to examine the composition and the physicochemical properties of the biomass. It is found that the alkali and alkaline earth metals (AAEMs) in RS were obviously removed by acid pickling, especially HCl. Fixed bed pyrolysis data showed that liquid product increased from 37.48 wt % (RS) to 42.24 wt % (RS-HCI), 48.03 wt % (RS-HF), and 47.20 wt % (RS-HCl + HF). The relative content of main compounds in bio-oil were identified by GC/MS. Sugars increased from 1.43% (RS) to 25.27% (RS-HCl), 19.00% (RS-HF), and 19.78% (RS-HCl + HF). Particularly, D-allose, which has been widely used in the field of healthcare, increased dramatically. It is proposed that the removal of AAEMs promoted the depolymerization of cellulose or hemicellulose, resulting in increased sugars. Current results provide greater feasibility using bio-oil as raw material in biorefinery process.